The proposed research focuses on the motor control and motor coordination of complex vocal communication in songbirds. Song production in birds involve coordination of the vocal and respiratory motor systems and, thus, represents a motor task similar to the control of human speech and singing. Furthermore, motor patterns for song production are learned in a way that parallels vocal learning in human infants. A number of peripheral motor correlates of song, including recordings of bronchial airflow patterns, subsyringeal air ac pressure, electromyography and sonomicrometry of syringeal and respiratory muscles will be studied to illuminate motor the muscles of both sides of the vocal organ as well as the expiratory and inspiratory muscles. Synchronization of vocal and visual displays will be explored for the first time. Information gained from this research will not constitute a description of the peripheral motor patterns but, at the same time, outline the specific tasks of the central motor control. The sonomicrometric information during spontaneous vocal behavior will provide the first evidence on muscle shortening patterns for any vocal system including the human larynx. In addition, physical and neuromuscular constraints on vocal production will be explored by comparing motor correlates of heterospecific vocal mimicry to those of the tutor species. Specific questions that can be addressed include the variance of invariance of motor gestures for acoustic communication, physiological and morphological constraints on motor performance and bilateral processes leading to lateralized behavior. The integrative nature of this research will generate results of wide interdisciplinary interest, including disciplines such as neurobiology, respiratory physiology, linguistics, neuroethology and evolution.